Since the hydraulic clutch system operates on brake fluid, you should also read the relevant material in the section "Bleeding the brake system".
Raise the car from the front, see item 29.
Check the brake fluid level in the clutch expansion tank and, if necessary, top up the brake fluid to the "max" mark.
Remove the boot from the air release valve on the slave cylinder.
Carefully ensure that the valve rotates easily.
Place the free end of the hose in a container half filled with brake fluid; the end of the hose must be below the liquid level.
Slowly press the clutch pedal several times (an assistant is required).
Keep the pedal pressed and unscrew the air release valve screw until brake fluid starts to come out. Then close the valve again.
Release the clutch pedal, press it again and hold it in this position. Open the air release valve and close it again. Repeat this process until the air bubbles in the leaking brake fluid disappear. In this case, you should constantly add brake fluid to the expansion tank.
Remove the hose and put the boot on the air release valve.
Add brake fluid to the expansion tank up to the "max" mark.
Lower the car, see item 29.
Test drive and check the clutch operation. The gears should shift easily without grinding, otherwise repeat the bleeding process or determine another possible cause using the diagnostic table.